Concrete block mold



Feb. 1, 1949. F. KREGER I CONCRETE BLOCK MOLD Filed Sept. 5, 1946 2 Sheets-Sheet 2 Patented Feb. 1, 1949 UNITED STATES PATENT OFFICE 2,460,697 j CONCRETE BLOCK MOLD Lawrence F. Kreger, Chicago, Ill. Application September 5, 1946,1Serial No. 694,870

Claims. (01. 25-419) The invention relates generally to molds for making concrete blocks or the like, and more particularly to a mold for this purpose adapted to be manipulated by hand. i

The general object is to provide a novel mold of the foregoing character, which is easy to handle, and which may be inexpensively manufactured.

Another object is to provide a novel mold of the foregoing character, which may be made entirely of sheet metal, thus rendering it much lighter in weight and easier to handle than molds involving relatively heavy cast parts.

A further object is to provide a novel mold of the foregoing character which, when the block is ejected, has a. thickness or depth only slightly greater than that of the block, thus rendering it of minimum size for storin and shipping.

Still another object is to provide a novel mold of the foregoing character, having an ejector constructed in such a manner that accumulations of cement or concrete spilled on the mold during use cannot interfere with complete movement of the ejector, so that the blocks made with the mold will be uniform in thickness or depth.

A still furtherobject is to provide a novel mold of the foregoing character, which may be made entirely of sheet metal parts welded together, thus rendering it inexpensive to manufacture on a quantity basis.

Another object is to provide a novelmold of the foregoing character which, while made of sheet metal, is sufiiciently rigid to produce accurately formed blocks and to withstand rough usage.

Other objects and advantages will become ap-' parent from the following description taken in connection with the accompanying drawings, wherein: I w

Figure 1 is a perspective viewof a concrete block mold embodying the features of the invention and showing the mold in position for filling it with concrete.

Fig. 2 is a perspective view of the mold shown in Fig. 1 but with the mold inverted and in position for removal of the concrete block.

Fig. 3 is a longitudinal vertical sectional view, on an enlarged scale, of the mold, with the mold inverted as in Fig. 2. i

Fig. 4 is a transverse sectional view of the mold with the mold positioned as in Fig. l.

Concrete block molds of the character herein contemplated are adapted to be manipulated by handand are so constructed as to mold one block at a time. The type of block for which the present mold is adaptedis of standard form, being hollow to reduce its weight and to provide a heat-insulating dead-air space within a wall constructed of such blocks. While I have shown herein a mold provided with a certain number, and type of cores,'the invention, of course, is not limited to a mold making this particular form of block,,the particular form of mold herein shown being merely a mold suitable for making oneof a number of standard types of blocks.

The mold disclosed herein comprises generally.

a rectilinear frame in which a number of cores are positioned so that the resulting block is hollow. Mounted within the frame. is an ejector plate which functions as a bottom for the mold when the concrete is being placed therein. After the concrete has been suitably tamped, settled within the mold, and leveled off, the mold is adapted to be inverted for removing the block therefrom. When the mold is so inverted, the ejector plate is held against movement while the frame is removed upwardly 'or stripped from the block, thus removing the block from the mold and depositing it in position for hardening.

I n order that the mold may be continuously used, the concrete mix adapted to be used with a mold of this type is a so-called dry-mix, in

which the water content is sufiiciently low to.

permit'the concrete block to retain its shape after being ejected from the mold before it has had time to set. A simple test for determining whether the proper amount of water has been used in a mix is to take a handful of the mix,

squeeze it and then place it in position for setting. If any sagging of the form takes place, then, of course, the mix is too wet. In other words, the Water content of the mix should be limited to that which will permit the block to be ejected from the mold immediately after being formed therein.

Moldsof this character are particularly useful at isolated locations, such as farms, where the cost of hollow tile, brick or concrete blocks from a central molding plant would be exorbitant. It is also particularly useful for making blocks when only a relatively few blocks are'neded for any one job.

The particular embodiment shown herein is adapted to be constructed entirely of sheet metal with the parts thereof secured together as by welding. Thus, the mold may be readily manufactured at a relatively low cost and is light in weight (compared to many prior forms which utilize castings) so that it may be easily manipulatedby an individual. It is also so constructed that the parts thereof may be collapsed into a compact, form having a thickness substantially ferred form of construction, the frame com prises a pair of similar U-shaped members placed.

together to form a rectangle and secured together.

cut through such concrete or to crack it away so by plates -ll overlapping the ends of each mem ber and spot-Welded thereto. frame rigid, it is provided with outwardly .turnerziv flanges 12 extending around its entire periphery" at both faces thereof, the flanges thusholdmg' the frame in shape so that it cannot bulge outwardly when filled with.concrete. The end plates ll .are also provided with outwardly turned flanges ;I3 preferably' extending beyond f-thej flanges i2 and provide'convenient meansFb'y which the mold may begripped; V v t Located within the frame in spaced relation thereto is a; plurality of cores M for making" the block hollow. Each core" I4 is of box like' c'onstruction and preferably comprisesa strip-of metal wrapped into rectangular'form with*the ends thereof overlapped and weldedto' each: other, as indicated atl 5'. The-upper end of eacheerewnen the mold is positioned'for being filled with} concrete," is provided with an endclosure": p1atels so'that concrete-cannot; fall therethrough wher'rbeing dumped into the mold'i'; The end closure plates 'l6 are secured to the cores; was; by Welding and preferably are provided Withholes I1 to ifacilitate' withdrawal of -the '-block-* front the mold, should'a small layer of concrete be lef t extending-over the tops of the coresvg 1 i Each" core is rigidly secured in pla'ce by a strap: 20 having its ends-a'butting the face of one of-the' flanges l2 of the -frame and an I intermediate por'-' new of the-strap -20 bent into a U shape, assh'own at 2|, to be positioned within thefcore-and' spot welded "to the inner surfaces thereof. Thus, the cores are rigidly' held in place by straps 20, w ith the straps; bridging-the space between the frame and'the cores'.-; j The mold is adaptedto be -placed,-when itis {t'o befilled'withconcrete, with the closure plates- 6 of the cores upwardly and the straps atj-the; bottom -of the molds The mold preferablyis'" placedon asupport; such-{as a box A', extending only} under its 1 intermediate portion A{ bottom;

wall'for the' mold is provided by an ejector platef OfrectanguIar f rm and loosely fitting withinthe frame. The-plate 30 is'p'rovided' with aper tures 3 I through which the -cores I4eXtendL- The ejector pla'te-3ll thus provides a bottomwall inf the entire space between the corese'aiid the frame l0 wheretheconcretej is placed.-}When thmold isin-"the position' shoWnin Figs. 1 and4 =the'- ejector=:plate'is adapted to be supported by the straps 20; and the-:depth: or thickness of the block 'isthus determined by thedistancebetween th'ei ejector plate 30-and the top'of 'theframe? when so positioned.

In use, concrete 'is apt to'be' spilledflon -the straps v1 2, and such concrete'would prevent the platex30 from being-properly positioned at the bottom of the'mol'cL'if the plate 30*were to 'lie flat I against 1 the straps. zomsueh acondition would, therefore; result in blocks- 0f varying thicknesses. e To prevent this fromv occurring-the e ejectonplate -;3U-,v-sinstead of resting l directlylon' the straps 20, is provided with means providing a relatively small area of engagement with the To renderthe-" straps 20 so that concrete spilled on such straps will not interfere'with full movement of the plate.

In the present instance, the ejector plate 30 is provided with longitudinally extending angles 32 with one leg of each angle lying flat against the underside of the ejector plate 30 and welded thereto, ,and the other leg. of each angle projecting therefromgtofengage the straps 20 *edgewise. The edges of the angles have a blade-like action on any concrete spilled on the straps and tend to that the ejector plate is permitted to move fully to its. lowest point within the frame. Thus, even though concrete is spilled on the straps 20 during the"use of thedevice, the angles 32 will cut through any such spilled material and fully engage the straps 20 to permit the ejector plate to be properly positioned within the mold. V

[Afte the mold" ,h'a's"been' filled with" concrete and" he' con'crete properly' settled and tamp'edtherein, the "moldis inverted from the position shown in Fig. 1 to that shown inFig. -2 so'that theffe'jector plate enemie on' topof the block withrnftheinoldf The ejector mete is. "thenhelda'gai'n'st" upward movement while the moldis drawn upwardly to strip it from the block; To facilitate suchmovement of tlie moldfthe' ejector plaitegat its" ends,-isprovided with a pair of hand: gripsfindicated at -33;"so that the ejector platef maybe held'ag'ainst' movement while the moldis drawn upwardly; Eachhand grip preferably is' in' the form of asheet"-mtal-1plate"=having= a flange portiom 34 at one" end bent {to lie flat against the ejector plate and welded th'ereto. Eachh'an'd grip 33 isalso provided, at its opposite end, with a flange 'zpo'rt i'on "xteiiiiing outwardly --adjacerit* the flange "1 3 1 provided on the ad jzieiit'hd plate l -Wheh th e mb1d is in the position 'shown-in Figi'Z-the fingers-of each hand may be placed" under" The i flange 13 on the end plate! I while 'the-thumbf is meed n the flange 35 *of the grip of the fejector plate. By

- forcing the flange 13' to ard j the flan'ge'ti the' ejector plate "is held*against thetop -of the'block within t e, mold whil the; mud 'ie mevedmpwardly to' stripfit from-the mos. e he ejector prevent air pockets forming under th'e concrete whenth'e mold is beiiig'fille'd. -The aprtur'e s' 3fi also p'revent any vacuum 'foiming when 'theejec a The length 6 in'which position-the 'StraDE ZD silppoltiiig the o,

cores arefiatthe jlowen end 'ofthe mold. i when in this positiom thefejectbrplate will'fall' to the bottom-of the =frame "1 0 iw ith" ehehand-grips' 33 projecting below the fra' shown "Fig. 1.

Should there be any concrete colletited 'ori' the' up'per race of the "straps-20 from previou's use of the device, the edgewise engagement 'of' theangles 32 will tend-to cut"through such 'spilledmaterial or to crack ritaway sci" that" the ej-ector platewill be permittedvto fall ;-::to its fully? lowered position; as-shown in Eig'zz irc' if. Y

When the mold is thus placed, it is ready for filling with concrete. The concrete is poured or shoveled into the mold, tamped to cause it to completely fill the mold, and then settled by jarring the mold on the support A. The flanges IS on the end plates ll provide convenient means for grasping the mold to effect such jarring. The concrete is then leveled off flush with the upper flange l2 of the frame it, when so positioned.

The block then is ready for ejectment from the mold and, for this purpose, the mold is removed from the support A and is inverted. This places the mold in the position shown in Fig. 2 and the flanges l3 on the plates I! together with the flanges on the hand grips 33 of the ejector plate may be grasped to hold the ejector plate against upward movement while the frame I0 is drawn upwardly from the block. The mold is thus stripped from the block and the block is left to harden. The mold, however, may be immediately used for forming another block.

The mold is relatively light in weight since it is made entirely of sheet metal. It is rigid in character and capable of withstanding rough usage without becoming bent out of shape since all of its parts are sufiiciently reinforced or formed in such a manner as to avoid being readily bent. When the mold is not in use, it occupies a minimum of space since the hand grips 33 of the ejector plate lie within the frame l0 and do not protrude materially beyond the frame. The edgewise engagement of the angles 32 with the straps 20 provides adequate support for the ejector plate when serving as a bottom wall for the mold and will properly position the ejector plate so that blocks of uniform thickness are produced thereby.

I claim:

1. A concrete block mold comprising a rectilinear mold frame, a plurality of cores located within said frame in spaced relation thereto, straps for holding said cores in place and bridging the space between the cores and the frame, an ejector plate movable in said space and limited for movement in one direction by said straps, and means on said ejector plate for engaging said straps to effect such limitation of movement of the plate and having a relatively small area of engagement with the straps to prevent concrete spilled on said straps from interfering with movement of the plate. j

2. A concrete block mold comprising a rectilinear mold frame open at opposite faces, a plurality of box-like cores located within said frame in spaced relation thereto, straps secured at their intermediate portions to said cores and at their ends to one face of said frame thereby bridging the space between the cores and the frame, and an ejector plate fitting within said frame and about said cores and movable from one face of the frame toward the other, said plate having reinforcing means adapted to engage the inner face of said straps edgewise to limit movement of said plate in one direction, the edgewise engag-ement of said means with said straps preventing concrete spilled on said straps from interfering with full movement of said plate toward said straps.

3. A concrete block mold comprising a rectilinear mold frame open at opposite faces, a plurality of box-like cores located within said frame cores and in spaced relation thereto, straps secured at their intermediate portions to said cores and at their ends to one face of said frame thereby bridging the space between the cores and the frame, and an ejector plate fitting within said frame and about said cores and movable from one face of the frame toward the other, said plates having reinforcing angles secured thereto with one leg of each angle fiat against the plate and the other leg projecting therefrom to engage said straps edgewise to limit movement of the plate, the edges of the angles providing a blade action on any concrete spilled on said straps to provide for full movement of said plate toward said straps.

4. A concrete block mold comprising a rectilinear sheet metal mold frame having outwardly extending flanges at both of its faces, a plurality of box-like cor-es located within and spaced from the sides of the frame, a plurality of straps for holding the cores in place, each strap being secured at its ends to the flange on one face of the frame at opposite sides thereof, the intermediate portion of each strap being U-shaped and extending into the core a substantial distance and secured thereto to rigidly hold the core within the frame, an ejector plate movable within the frame and having apertures through which the cores extend, said straps limiting movement of the plate in one direction, and hand grips rigidly secured to said plate and engageable with said frame to limit movement of the plate in the opposite direction.

5. A concrete block mold comprising a rectilinear sheet metal mold frame having outwardly extending flanges at both of its faces, a plurality of box-like cores located within said frame in spaced relation to the sides thereof, a plurality of straps secured intermediate their ends to said extending outwardly with their ends secured to one of the flanges of the frame for rigidly holding the cores in place, an ejector plate movably positioned within the frame and having apertures through which the cores ex'- tend, and hand grips for moving said plate to eject the block from the frame, each hand grip comprising a sheet metal plate having a flange portion at one end bent to lie flat against the ejector plate and secured thereto and a flange portion at the other end bent outwardly to be gripped with the adjacent flange on the frame for moving the ejector plate in ejecting the block, said hand grips having a length substantially equal to the depth of the frame whereby the mold when not in use may be limited to a dimension substantially equal to the depth of the frame.

LAWRENCE F. KREGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,508,336 Jamison Sept. 9, 1924 1,534,354 Besser et a1. Apr. 21, 1925 1,717,676 Garvin et a1. June 18, 1929 2,290,340 Leach July 21, 1942 2,397,223 Valdastri, Sr. Mar. 26, 1946 

